Enhanced variable rate codec (EVRC) is a codec used in code division multiple access (CDMA) networks for optimized coding of human speech signals. The EVRC is extensively used in wireless networks, such as cellular networks, to minimize the amount of noise transmitted with the human voice over wireless networks.
Today, a cell phone user can utilize a variety of value-added services. One such service includes tuning into a news broadcast using the cell phone. The news broadcast typically includes background music. In such a scenario, the voice-centric approach of the EVRC codec interprets the background music as noise and attenuates the broadcast signal. As a result of this attenuation, whenever music is played along with voice at the transmitter, the cell phone user hears nothing because the signal is attenuated whenever the music is present.
Existing methods of playing background music along with voice on the CDMA network are also inefficient in that they increase the latency of a encoder on the CDMA network and in effect the complexity of the encoder. An efficient method and solution is thus required to play voice with background music on a CDMA network that uses the EVRC codec.